1. Field of the Invention
The present invention relates to a drive system, an endoscopic system comprising the drive system, and a control device for the drive system.
2. Description of the Related Art
An endoscopic system, in which a rotary cylinder with a rotatable spiral convex portion is circumferentially provided on an insertion section, is disclosed, for example, in Jpn. Pat. Appln. KOKAI Publication No. 2007-319547. In Jpn. Pat. Appln. KOKAI Publication No. 2007-319547, the following technique is disclosed. In this endoscope, the rotary cylinder rotates around a longitudinal axis for the spiral convex portion to gather nearby tissues, and for the insertion section to advance or retreat in the longitudinal axis direction. Provided at the distal end portion and proximal end portion of such rotary cylinder are sensors for detecting the number of rotations. Based on the difference in the number of rotations between the distal end portion and the proximal end portion, the power supply to a motor for rotating the rotary cylinder is controlled.
In an endoscopic system which comprises a power unit such as the rotary cylinder mentioned above, in order to allow the insertion section to advance and retreat, it is necessary for a rotating body of the power unit to be able to rotate in both the forward and reverse directions. Here, preferably, the drive circuit including a power source and a configuration for switching directions of rotation should be simple. However, the rotation needs to be controlled with precision.